I have estimated my roof to be about 9.5 squares. The roofer estimated that he would need close to 12 squares to do the job. How much extra should be allotted for Starters and Caps? I am having cobra ridge vents and Timberline Architectural shingles put on.

Can you post up a photo or @ least a line drawing? Sounds like they are allowing for ‘waste’ & you are not.

Typical is 10% for a gable roof, 15% for a hip.

If you are that concerned, you can always request any extra material be transferred in ownership to you, that way they aren’t buying parts from your job to use on another (depending on how your deposit structure is based).

As to how much is hip & ridge, well… that depends (again) on what type of roof profile you have. A ‘basic’ hip box will have 5 runs whereas a basic gable will have one.

9.5 x 1.1 = 10.45, or 10.66 with rounding up, however I could easily see this go 10.33 with a crew that doesn’t throw away every little bit of cut shingle.

It is possible they are going with the added shingles as ‘starter’ & if this is the case, I would ask them to go 10.66 on shingles (less however many feet of field converted to ridge cap) & ASK THEM TO PURCHASE ‘REAL’ STARTER.

I don’t like 3T’s cut back for use as starter unless I absolutely have to (i.e. ran short or something) & most crews won’t go the added step to cut it back anyhow.

Try & ask how many linear ft. of drip edge they are calling for & if this # includes the rakes or only the eaves. If it’s rakes AND eaves, then convert this # over to ‘true’ starter.

Most contractors would rather have a square left over than a square short, if you don’t figure the starters and ridge you run short and it comes out of their pocket not yours. I give a price for the whole job , what difference does it make if I run short or have a square left over , the price is still the same. Some I win , and some I loose. You don’t like the price get some other estimates. As good as I am , I can’t figure one to the tab.

I also do not give a square break down.I also bring more than enough material to do the job,and take extra with me when I leave…Sometimes I show up w/a full box of drip edge, I use 14 pcs. and take the excess to next job I keep the box just to transport without damage…I think that it is unprofessional to give material breakdown…My contracts specify materials to be used only not quantity…I will however leave an open bndl. for the H.O. if they have a place to store it.Most times they don’t want it…I don’t do jobs that the H.O. wants to buy materials and get a price for install…My contracts include permits,mat. labor and disposal. No price break down…

I also do not give a square break down.I also bring more than enough material to do the job,and take extra with me when I leave…Sometimes I show up w/a full box of drip edge, I use 14 pcs. and take the excess to next job I keep the box just to transport without damage…I think that it is unprofessional to give material breakdown…My contracts specify materials to be used only not quantity…I will however leave an open bndl. for the H.O. if they have a place to store it.Most times they don’t want it…I don’t do jobs that the H.O. wants to buy materials and get a price for install…My contracts include permits,mat. labor and disposal. No price break down…

I don’t know of any contractors that does that either, if I’m low on the bid the homeowner isn’t going to pay extra, a price is a price no matter what the outcome.